Distributing arbitrary lambdas and lazy computation of any sort is extremely difficult in GHC Haskell, hence the complexity and limitations of cloud Haskell. Unison makes a number of design choices to support distributed lazy computations.

This is not to say unison style computations on GHC Haskell are impossible. For the start of serializing lazy computations see https://github.com/jberthold/packman or http://hackage.haskell.org/package/ghc-heap-view-0.6.0. I would love if Unison's hashing model was added to GHC, but Haskell compiled to WASM is a more likely candidate for obtaining hashes.